1. Field of the Invention
The present invention relates to a processing condition selecting apparatus, a processing condition selecting method, and a storage medium storing a program for selecting a single signal processing condition from a plurality of signal processing conditions representative of different dot distribution characteristics, and for instructing an image forming apparatus, which is capable of producing a print by forming an image on a recording medium, to carry out a halftone process depending on the selected signal processing condition.
2. Description of the Related Art
With significant advances in inkjet technology in recent years, it is becoming possible for inkjet image forming devices to produce large color prints of high quality at high speeds. Inkjet image forming devices are widely used particularly in sign and display applications, and are applicable to, for example, prints on POP (point of purchase) posters, wall posters, outdoor advertisements, billboards, etc. Inkjet image forming devices are capable of producing prints by forming a number of ink dots on a print medium, by applying droplets of different colored inks, e.g., C, M, Y, K inks, to the print medium.
Inkjet image forming devices perform a halftone process on an image signal representative of multiple gradation levels to convert the image signal into a discharge control signal, which represents dot on/off information and dot size information, for controlling the discharge of ink droplets. There have been proposed various image processing technologies for selecting an appropriate halftone process to increase the quality, particularly the image quality, of prints.
Japanese Laid-Open Patent Publication No. 2010-239668 discloses an apparatus for and a method of performing a halftone process using a threshold matrix, which has an anisotropic threshold array characteristic, in order to reduce banding in a scanning direction of relatively low output accuracy in an image forming device with anisotropic output accuracy.
Japanese Laid-Open Patent Publication No. 2000-196885 and Japanese Laid-Open Patent Publication No. 2010-136232 disclose a method of and an apparatus for performing a halftone process by selecting either one of a resolution-oriented threshold matrix and a gradation-oriented threshold matrix based on local characteristics of an input image signal. For example, the threshold matrix is resolution-oriented for an image area having a large gradation change, such as a character area, a line image area, or the like, and the threshold matrix is gradation-oriented for an image area having a small gradation change, such as a photographic image area or the like.
Japanese Laid-Open Patent Publication No. 10-032712 discloses an apparatus for and a method of performing a halftone process by selecting a dithering process for an image area such as a graph, a computer graphic (hereinafter referred to as a “CG”) image, or the like, or an error diffusion process for an image area such as a natural image or the like.